Fuse link



Nov. 2, 1943.

A. G. STEINMAYER FUSE LINK Filed June 12, 1941 A INVENTOR, n k

v ATTORNEY.

Patented Nov. 2, 1943 v FUSE LINK Alwin G. Steinmayer, Milwaukee, Wis., assigner corporation of Delaware to LineMateriai Company, MilwaukedZVis., a.A Application June 12, 19 41, Serial No.

4 Claims. (Cl. 20D-135) This invention relates to improvements in fuse Fuse links of a well known type comprisea mechanically delicate fusible section electrically connected to conductor terminals, means for biasing the fusible section, and an insulating tube mounted over the fusible section.

Heretofore assembly of the above noted parts was such as to permit movement, as hyA twisting or turning, of the conductor terminals relative to each other .and to the fusible section. This relative movement of the conductor terminals caused the delicate fusible section to Abecome damaged mechanically, thereby destroying the predetermined electrical characteristics of the delicate fuse wire and causing it to operate at values diilerent from its predetermined calibrated values.

Therefore, it is an object of this invention to 'provide for a fuse link means adapted to prevent relative twisting or turning movement of the fuse link terminal members.

More specifically, it is an object to provide a fuse link having conductor terminalsv mounted in interlocked relationship with the fuse tube, thereby preventing turning movement of the terminals relative to each other and to the fusible section.

Another object is to provide a fuse link wherein the conductor terminals are-directly coupled against relative turning movement hiv means ofv the fuse tube.

In the drawing:

Fig. 1 is a view in' side elevation, partly inv section, showing the improved fuse link.

Fig. 2 is a view in side elevation taken at a right angle to Fig. 1.

Fig. 3 is an enlarged view taken on the line 3-3 of Fig. 1. A

Fig. 4 is a view in side elevation, partly in section, showing a modified form of fuse tube adapted to be interlocked withthe fuse link conductor terminals.

Like parts areindicated by the same reference numerals throughout the several views.

The fuse device shown in the drawing comprises a conductor rod III to one end of which il secured a fusible section li comprising a strain wire I2 and a fusible wire I3, each secured to the rod in any suitable manneras by crimping or solder, not shown. A coil spring I4 are closely spaced to receive the threaded portion of the, nut I1.

`The upper end-of-each wire i 2 and i3 is secured to the reducedportion i8 of the conductor terminal I9.by means of solder 20.

The conductor terminal i9 comprises a flatl conductor terminal I3 and fuse tube 25 against turning movement relative to each other. The reduced portion i8 of the conductor I9 is received in the upper open end of the tube 25 and Y prevents lateral movement of the conductor i9 relative to the longitudinal axis of the tube 25.

'I'he lower end of the tube 25 is counterbored at 29 to form the seat 33 against whichrthe nut Ilis received. 'Ihe nut l1 and seat 30 cooperate to bias the spring lli against therrod I0 which in turn is held against movement bv the strain wire I2 which in turn holds the terminal i9 and tube 25 against axial movement away from each other.

The rod l0 is held against turning movement relative to the tube 25 by an anchor means 3|. Before the anchor means 3| is crimped into fixed position with the rod I0 it is circular in form. The circular collar means is then placed in any suitable forming machine (not shown) and partially vflattened to form the ears 32 extending laterally from opposite sides of the circulary hub portion 33. The hub portion/33 ls oversized, thereby permitting it to be slidably vreceived over the lower end of the rod i0. The

anchor means 3i is moved upwardly on the rod l0 to interlock the ears 32 with the notches 28.

`The hub portion 33 of the anchor means is then crimped onto the lrod i0, securing the anchor.

31 having a seat 38.

The tubes 35 and 36 are held against movement relative to each other in any suitable manner.

The lower end of the tube 36 is notched at 39 to receive the ears 32 of the anchor means 3|, whereby the rod I is held against turning movement relative to the tubes 35 and 36.

The upper end ofthe tube 35 is notched at 40 for the purpose and in the manner described with reference to Fig. 1.

Under short circuit c-onditions the fusible section Il melts, permitting the expanded spring i4 to eject the conductor rod I0 out of and away from the lower end of the tube 25. The extended arc established between the ruptured ends of the fusible section is extinguished by the expulsion action of the' tube 25. After the arc has been cleared, all of which occurs in a comparatively short interval of time, the tube 25 falls clear of the terminal 2'.

It is to be noted that the fusible section Il is protecte-d against mechanical damage through being turned or twisted, by the interlocked relationship of the fuse tube 25 to the conductor terminals I0 and i9 to each of which the fusible section is directly connected.

From the foregoing description it is apparent that the objects of this invention have been accomplished by providing a fuse link having conductor terminals interlocked against movement relative to each other, whereby the fusible sec'- tion directly connected therewith is protected against electrical damage.

I claim: i

l. A fuse link comprising spaced conductors, a fusible section connectingy said conductors, a first tube notched at one end, a second tube forming an anchor receiving chamber with said first tube, and being notched adjacent said chamber, biasing means anchored in said chamber and to one of said conductors, and means on each of said conductors received in said notched tube ends whereby said conductors are coupled against relative turning movement and free to move axially apart under short circuit conditions.

2. In a fuselink, a tube of insulating material, a fusible section within the bore of said tube and extending lengthwise thereof, said fusible sec-- tion being torsionally weak, a rigid terminal member extending lengthwise into one end of said tube and projecting externally thereof away from said tube in a direction parallel to the axis of said tube, said tube being notched to normally engage said terminal member whereby to prevent rotation oi `said terminal member relatively to said tube, one end of said fusible section being connected to said terminal member, a rod-like terminal member connected endWise to the other end, of said fusible section within said tube, said rod-like terminal member extending lengthwise of and projecting out of and beyond the other each other to provide a nut receiving chamber i end of said tube, and a collar secured to said rodlike terminal member and having a pair of ears extending laterally from said member, said other end of said tube being notched to normally engage said ears and thereby prevent relative rotation between said tube and said rod-like ierminal member, the arrangement being characterized in that said rod-like terminal member is free to drop out of said tube upon severance of said fusible section.

v 3. In a fuse link, an elongate tube of insulating material having a diametrically extending notch formed in each of its two ends, a conductive terminal member of ilat strip stock telescoped at one end into one end of said tube and in engagement with the aforementioned notch in said one end of said tube whereby to prevent relative rotation between said terminal member and tube, said terminal member extending beyond said tube in a direction lengthwise of said tube, a rod-like conductive member projecting into the bore of said tube at the other end thereof, a torsionally weak fusible section within said tube and interconnecting said terminal member and said rod-like con ductive member, a spring operative to eject said rod-like conductive member from said tube upon severance of said. fusible section, but normally restrained by said fusible section, and means secured to said rod-like conductive member and engaging the notch in the other end of said tube whereby to prevent relative rotation between said rod-like conductive member and said tube.

4. In a fuse-link. an elongate tube of insulating material having a diametrically extending notch formed in each of its two ends, a conductive terminal member of fiat strip stock telescoped at one end int one end of said tube and having shoulders which engage the notchlih said end of said tube and which determine the extent to which said terminal member projects into said tube while preventing relative rotation between said terminal member and tube, said terminal member extending beyond said tube in a direction axial of said tube, a. rod-like conductive member projecting into the bore of said tube at the other end thereof. a torsionally weak fusible section within said tube and interconnecting opposed ends of said terminal member and rodlike conductive member, respectively, a normally tensioned helical spring coiled around said rod like conductive member, said spring being dctachably anchored at one end to said tube and at the other end to said rod-like conductive member, said spring being operative, upon severance of said fusible section, to eject said rod-like con? ductive member from the bore of said tube, and means for preventing relative rotation between said tube and rod-like conductive member, said means being secured to said member and in engagement with the notch in the other end of said tube.

ALWIN G. STEINMAYER. 

